For years, manufacturers have produced special containers for transporting, storing and processing data storage disks, substrate wafers, and the like. The common denominator with such articles is that they are particularly sensitive to contamination and therefore require extraordinary care when handling to avoid such exposure. Although the containers may be provided with cover members for safeguarding the disks from external impurities, a significant threat of contamination arises within the container itself in the form of airborne particulate which may settle on the disks and cause imperfections. Particulates may constitute subminiature fragments of the material used to manufacture the disk cassette and can arise from the abrasion which occurs between the disk cassette and the disks when the disks rotate, rattle, or experience disk tilt within the disk cassette. Main sources of disk rotation, rattle, and tilt include movement of the disk cassette, such as during transportation and handling.
With regard to data storage disks, particulates have the effect of tainting the data storage medium is a quality control issue which results in a reduced ability to store and/or retrieve data.
Conventional disk shippers have a rectangular cassette having an open top and open bottom, elongate sidewalls that converge in at the open bottom, and ends with U-shaped openings extending down from the top edge. A plurality of parallel rib members or teeth extend down the inside surfaces of the sidewalls defining slots therebetween. A top cover attaches over the cassette to close the open top and U-shaped opening on the cassette ends. The top covers conventionally have locators configured as teeth or protrusions extending centrally down the inside of the top cover for individually engaging and constraining and locating each disk in the cassette. Also, it is known that the top cover may also have, polymer strips running parallel to the locators on both sides of the locators. These strips often called anti-clocking ribs or strips, are intended to minimize disk rotation and do not have discrete individual features for engaging individually the disks. See U.S. Pat. No. 4,557,382 and U.S. Pat. No. 6,902,059, both assigned to the owner of the instant application, for example of such three piece disk shippers, both incorporated by reference herein.
The disk engagement portions in such prior art carriers have difficulty engaging the disks uniformly across the array of disks. Particularly spring supported teeth such as illustrated in U.S. Pat. No. 5,253,755 owned by the owner of the instant application. The top cover being latched at its ends tends to bow outwardly in the middle of the top cover providing the disks in the middle of the carrier less downward constraint that the disks near the ends. It would be advantageous to correct this non-uniformity of disk engagement by the top cover.
Disks shipped in these shippers now have different standardized thicknesses, in particular, 0.025, 0.0315, 0.040, 0.050, 0.069 inches are now in use. Conventional commercially available cassettes are configured for carrying a single size of disk, both diametrically and with respect to thickness. Attempts to insert a thicker disk in a carrier designed for a thinner disk, for example a 0.050 inch disk in a carrier designed for a 0.0315 inch disk will, at least, likely result in damage to the disk and will create difficulty removing the disk.
Similarly, putting a thinner disk in a conventional cassette designed for a larger disk will typically allow excessive misalignment resulting in potential disk damage and particulate generation as well as difficulty installing the top cover. Such damage to the disks can occur, for example, by contact between adjacent disks and disk tilting and rattling. The tilting and rattle also causes particulate generation. In that conventional locators on the top cover are configured for a specific thickness of disk, tilted disks may miss the disk edge receiving region on the locators when a conventional top cover is installed causing disk damage and/or particulate generation, as well as difficulty installing the top cover.
The length of cassettes, and correspondingly the disk shippers has been standardized, in that equipment at manufacturing facilities is designed to accommodate the particular sized cassettes. Manufacturers have been adding more slots with less distance between the disks to allow a particular size, length wise, of cassettes to ship more disks, this is particularly true for the thinner disks. Exteriorly, the cassettes are the same, however, the interior differs with a higher density of slots, correspondingly with less spacing or pitch between adjacent slots. Typically, a different cassette, and a different top cover is needed for each size (thickness) of disks and, of course, for different capacities, and certainly for different diametric sizes. Such complexities can cause inventory and part selection issues, e.g., which top cover to use for a certain disk thickness, or certain capacity carrier, when the disks are packaged and shipped.
The components for these shippers are manufactured by injection molding polymers, often polycarbonate for the cassette, and polyethylene or other polymers for the top cover and bottom cover. When different arrangements of top cover locators are needed to accommodate the different numbers of disks, and the different thickness, expensive tooling is needed for each arrangement. That is the steel molds, or different inserts for the molds need to be created to handle the array of combinations of capacities and thicknesses. To the extent a particular design of a cassette or top cover can provide for less plastic resin, this advantageous from a cost perspective as well as environmentally.
It is now common in shipping disks in such containers to vacuum wrap the loaded disk shipper in a metalized bag and then a further secondary polyethylene vacuum bag.
Disk shipping containers are or have been designed and built to support each specific diametric disk size including disks sizes of 48 mm, 54 mm, 65 mm, 70 mm, 84 mm, and 95 mm diameters and thicknesses of; 0.069 inches (1.75 mm), 0.050 inches (1.27 mm), 0.040 inches (1.02 mm), 0.0315 inches (0.8 mm), and 0.025 inches (0.635 mm). To the extent more universality is provided in cassettes and top covers, more variety in flexibility in shipping options may be offered at less expense.
A need therefore exists for an improved disk shipper components that provide more universality whilst still addressing the issues of particulates, contaminants, and minimizing damage to the disks being shipped, as well as a need to minimize manufacturing costs, including injection molding tooling, a need to be environmentally friendlier to the environment. The inventions herein address the aforementioned. Such a disk shipper should take advantage of the now common place practice of vacuum bagging disk shippers.